public class MyLinkedList {

    class Node {
        public int val;
        public Node next;

        public Node(int val) {
            this.val = val;
        }
    }

    public Node head;
    public Node last;
    public int usedSize;

    /**
     * 入队
     * @param val
     */
    public void offer(int val) {

    }

    /**
     * 出队
     */
    public int poll() {

    }

    public int peek() {

    }

    public int size() {

    }


}
